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Cushing's Disease and Syndrome
Cushing's syndrome describes a clinical metabolic disorder where there is an excess of glucocorticoids (hormones) in the body.
Glucocorticoids are steroid hormones that are produced by the adrenal glands. These hormones are produced in controlled quantities to regulate carbohydrate metabolism. The production of glucocorticoids by the adrenal gland is regulated by the pituitary hormone ACTH. The pituitary, located at the base of the brain, ultimately controls the output of glucocorticoids by the adrenal glands.
Excess glucocorticoids can be found in the body when the adrenal glands "over-function." This can occur in at least one of the following two ways:
1. Adrenal gland tumors: Here there is an increased production of glucocorticoids by the adrenal tumor itself (Cushing's syndrome).
2. Pituitary tumors: Here there is an increased production of ACTH. The ACTH serves to stimulate the adrenal glands to produce excess glucocorticoids. This condition is referred to as Cushing's disease.
An additional important cause of excess glucocorticoids (Cushing's syndrome) is iatrogenic (medically induced). In this case the symptoms of Cushing's syndrome are secondary to glucocorticoid medications (e.g. methylprednisolone, dexamethasone, hydrocortisone).
The Effects of Excess Glucocorticoids in the Body
1. Increased blood glucose levels
2. Central obesity (sparing the limbs)
3. Hypertension
4. Absent menstrual cycles
5. Osteoporosis
6. Skin striae (discolored purple stretch marks)
7. Muscle atrophy/weakness
8. Increased body hair (hirsutism)
9. Low blood potassium
10. Swelling
11. Kidney stones
12. Changes in mental status (emotional lability or psychosis)
13. Delayed wound healing
14. Thinning of the skin (becomes more fragile and susceptible to injury)
Evaluation and Treatmento of Cushing's Disease
Evaluation of suspected cases involves blood testing for adrenal hormones and pituitary hormone (ACTH). Radionuclide scanning and/or CT-scanning of the adrenal gland may be necessary in some cases. The endocrinologist is the expert in the evaluation and treatment of this disorder.
Treatment of Cushing's disease requires surgical excision of the pituitary tumor. Adrenal gland tumors will also require surgical removal. Treatment of Cushing's syndrome as a result of glucocorticoid medications requires careful readjustment of steroid doses by the physician. This can often be difficult when the glucocorticoids are often necessary to control an underlying disease process (e.g. lupus, COPD, asthma, rheumatoid arthritis).
The abrupt cessation of glucocorticoid medications after long-term use can be life threatening and result in distributive shock progressing to death. For this reason, a special steroid tapering regimen must be implemented.
I hope that this article will provide you information about cushing's disease and syndrome,
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